1. Field of the Invention
The present invention relates to a color coding method and apparatus and, more particularly, a color coding method and apparatus for an X-ray positioning system.
2. Description of the Related Art
The dental X-ray is vital to the diagnosis and treatment of the patient's teeth. The dental X-ray provides the dentist with a quick and accurate picture of the patient's teeth with which the dentist initially diagnoses a new patient's teeth and determines the course of treatment which may include root canals, cavity feelings, wisdom teeth extractions, etc. Since the dental X-ray provides the dentist with an interior picture of the teeth, the dentist can determine almost immediately what the condition of the teeth is and what course of action to take in the treatment of the teeth. The dental X-ray is so fundamental to the dentist's practice that it is the first thing the dentist requires when treating a new patient.
Dental X-raying techniques have evolved over the years. The most primitive dental X-ray technique involved the dentist placing a small X-ray film within the patient's mouth and exposing the X-ray film to X-rays from an X-ray machine emitter which was placed proximate to the patient's face such that the X-ray is directed to the X-ray film.
It was determined that the best quality X-ray images were obtained by the so-called "paralleling technique" whose basic principle for intraoral periapical films is that the film and the long axis of the tooth being radial graphed is parallel to each other, and the central ray of the X-ray beam is directed perpendicular to both. To accomplish this parallelism, it was determined that the object, i.e. tooth, to film distance must be increased.
Problematically, this object-to-film distance was sizeable in some areas, such as the maxillary molar position where the X-ray film was held in the midline of the palate of the mouth, to achieve this parallelism. This made holding the X-ray film in the patient's mouth difficult while the X-ray film was exposed. Another problem is that the increased object-to-film distance resulted in a loss of image definition, or sharpness.
In order to compensate for this loss of definition due to the sizeable object-to-film distance, it was found that a 16 inch focal film distance was necessary. To implement the 16 inch focal film distance, a long cone was attached to the X-ray emitter which functioned to provide this distance. Unfortunately, the "long cone technique" as it has become to be known, emphasizes the length of the PID rather than the parallel relationship of the object and the film.
In order to assist the dentist in positioning the film parallel to the teeth with such a long cone, positioners were developed which couple the cone to the film such that the cone and film are in alignment. As shown in FIG. 1, for example, the positioner comprises an aiming ring 100 which attaches to the cone 102, an indicator arm 104 which is held by the aiming ring and a bite-block 106 which holds the X-ray film. With this arrangement, the dentist need only position the film parallel to the teeth and the film, teeth and cone are in alignment such that the film and the teeth are parallel and the cone of the X-ray beam is perpendicular to both.
However, positioners do not take into account the different areas of the patient's mouth, known as the four quadrants. Problematically, each of the four quadrants of the patient's mouth requires different types of X-ray films, has different bites and is in different positions of the patient's mouth. Thus, there are different X-ray films for X-raying different teeth, different bite-blocks to receive different bites from the patient's mouth and different indicator arms for positioning the X-ray film in the proper position in the areas of the patient's mouth. In addition, the aiming ring needed to be modified for different positions in order to properly direct the indicator arm to the desired area of the patient's mouth.
This led to the dental practice of interchanging the X-ray films, the bite-blocks, the indicator arms and the aiming rings to achieve parallelism when X-raying different teeth in the patient's mouth. Problematically, the many interchangeable X-ray films, bite-blocks, indicator arms and aiming rings were confusing which resulted in the dentist needlessly wasting time determining the correct "set-up" for the desired teeth to be X-rayed. In practice, the dentist found that the proper combination of interchangeable parts could be found only through trial and error leading to further wasted time and discomfort of the patient. In addition, dental assistants likewise found the interchangeable parts confusing and often required the assistance of the dentist which detracted the dentist from other duties such as attending to other patients in the dental office. Since the patient's bill is based on the amount of time the dentist and dental technicians spend with the patient, the unnecessarily wasted time determining the correct combination of interchangeable parts for performing the dental X-ray was reflected in the patients bill.
Heretofore, there has been no system by which the dentist or dental technician quickly and easily determines the correct combination of X-ray film, bite-block, indicator arm and aiming ring for a particular dental area to be X-rayed.